Diamond Cutting

The first improvements on nature's designsplitting a stone along its grain by striking it. A
involved a polishing of the crystal faces, whichrough stone is cleaved if there are conspicuous
was called the "Point Cut". As further refinementdefects and/or inclusions which would prevent it
progressed, one half of the crystal would be cutfrom being made into a single gemstone. Cleavage
off, creating the "Table Cut". At the time,is the tendency of crystalline materials to split
diamonds were valued primarily for their lusteralong definite planes. Due to its atomic structure,
and hardness. Table Cut diamonds appeared blacka diamond can be cleaved in four directions parallel
to the eye. The Modern Round Brilliant cut (below)to each of the four octahedron crystal faces.
is the culmination of several hundred years ofCleaving is a critical step as a mistake by the
experimentation and development. Â"cleaver" could shatter the stone. Â Sawing:
Cutting a raw diamond into a faceted and polishedA stone-cutting saw is a thin disk made of
gem-quality stone is a multi-step process. Eachphosphor bronze. As the saw blade rotates it
step is critical to the final outcome. The steps are:continues to pickup or "recharge" itself with
Âdiamond dust which is the cutting agent. It can
- Markingtake several hours for the saw blade to cut
- Cleavingthrough a 1k rough diamond. Â Bruting: The
- Sawingrough is placed in a chuck on a lathe. While the
- Bruting (Girdling)rough stone rotates on the diamond lathe a
- Facetingsecond diamond mounted on adop is pressed
 Marking: A rough stone is marked prioragainst it, rounding the rough diamond into a
to cleaving or sawing to determine the directionconical shape. This step is also referred to as
of the grain or "cleavage", eliminate waste, androunding or bruting. Â
bypass inclusions or imperfections. The naturalFaceting: To facet a "Round Brilliant", a "blocker"
shape of the rough stone will also be a majoror "lapper" will cut the first 18 main facets, then a
factor in deciding how to cut the stone. An"brillianteer" will cut and polish the remaining 40
octahedron can be cut into one or two Roundfacets. The cutting (placing) and polishing of each
Brilliants but a square Princess cut will result in thefacet is accomplished by attaching the stone to a
least amount of waste due to the square shapedop stick and pressing it against a revolving cast
of the stone. Asymmetrical crystals suchiron disk, scaife, or lap on aÂ
asmacles are used primarily for fancy cuts. Cubic Facetron  that has been charged
shapes are ideal for a square Princess or Radiantwith diamond dust. During this faceting stage the
cut. High-tech computerizedhelium and oxygenangles of each facet must be cut to an exacting
analizers are now used to evaluate a stone priorstandard in order to yield maximum brilliancy and
to cutting. Â Cleaving: Cleaving refers tomaintain symmetry.